The present invention relates to synthesis techniques of metastable material using confined laser ablation, and provides an exemplary disclosure of techniques to fabricate diamond and transparent conductive amorphous carbon at room temperature.
Diamond and related materials have attracted renewed interest in recent years due to their outstanding mechanical, electronic and optical properties. New promising applications have been identified, including spin imaging, single photon emitters and high-speed electronic devices. However, these materials are not easy to synthesize, because the activation energy of graphite-diamond transition is so great that diamond synthesis requires extreme environments, such as high temperature and high pressure. Various synthesis techniques have been developed for obtaining metastable carbon materials, i.e. explosive detonation, chemical vapor deposition, and high-temperature high-pressure processing. However, the fabrication processes of these techniques are usually slow, complex and expensive due to the requirements of maintaining extreme environments. Some goals in the research of diamond and related materials are to lower synthesis temperatures, increase growth rates and reduce fabrication costs.
In addition, the details of the carbon transformation process still remain unclear in several respects. For example, there is a debate concerning the transition process between graphite-like carbon and diamond-like carbon. Some considered that the boundary between them was diffuse because of the amorphous nature of these materials, while others have argued that there is an abrupt transition between the two amorphous phases.